<!DOCTYPE html>
<html lang="zh">
<head>
    <meta charset="UTF-8">
    <title>15-box-sizing</title>
    <style>
        /** {
            box-sizing: border-box;
        }*/

        div {
            width: 150px;
            height: 150px;
            background-color: #f00;
            padding: 10px;
            border: 5px solid #ff0;

            /* box-sizing：用来控制width、height的含义
             1.content-box：width、height不包括padding和border

             2.border-box：width、height包括padding和border
             */
            /*box-sizing: border-box;*/
        }
    </style>
</head>
<body>

<div>我是div</div>

</body>
</html>